Quantitative Precipitation Forecast
Issued by NWS

Current Version | Previous Version | Graphics & Text | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
899
FOUS30 KWBC 111501
QPFERD

EXCESSIVE RAINFALL DISCUSSION
NWS WEATHER PREDICTION CENTER COLLEGE PARK MD
1001 AM EST WED JAN 11 2017

...VALID 15Z WED JAN 11 2017 - 12Z THU JAN 12 2017...
...REFERENCE AWIPS GRAPHIC UNDER...DAY 1 EXCESSIVE RAINFALL...


MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
35 ENE SCK 20 SSE AUN 15 E AUN 20 E AUN 35 SW TVL 50 SSW TVL
55 NE MCE 40 WSW MMH 35 ENE FAT 40 NE VIS 20 ENE PTV 30 ESE PTV
35 W IYK 35 E BFL 30 E BFL 20 E BFL 10 NE BFL 15 NNE BFL
15 N FAT 25 ENE MCE 30 NE MOD 35 ENE SCK.

MARGINAL RISK OF RAINFALL EXCEEDING FFG TO THE RIGHT OF A LINE FROM
POC 10 E BUR 10 N BUR 15 SSE PMD 20 N POC 20 NE ONT 30 NNE RIV
30 NE RIV 20 NW PSP 15 WNW PSP 20 E RIV 15 NNE RIV POC.


1500 UTC UPDATE

THE CHANGES TO THE PREVIOUS EXCESSIVE RAINFALL POTENTIAL OUTLOOK
WERE TO SEPARATE THE MARGINAL RISK AREA INTO TWO REGIONS.  THIS
WAS PRIMARILY FOR WHERE PRECIP IS FALLING AND IS EXPECTED IN THE
SHORT TERM.  ONE IN THE UPSLOPE SECTIONS OF THE SOUTHERN TO
CENTRAL SIERRAS...WITH THE SECOND OVER THE EASTERN PORTIONS OF THE
TRANSVERSE RANGE OF SOUTHERN CALIFORNIA.

GENERALLY COMPATABLE MODELS BLEND PRETTY WELL FROM LATEST
SATELLITE/BLENDED TPW TRENDS THAT SHOW A GRADUALLY DIMINSIHING AND
SOUTHWARD PUSH OF MAIN MOISTURE PLUME THAT HAS PROVED TO BE AN
EFFICIENT PCPN PRODUCER ACROSS MUCH OF CA. THE AXIS OF ABOVE
AVERAGE PW VALUES AND ONSHORE FLOW WILL REMAIN ENHANCED BY IMPULSE
PASSAGE INLAND/JET AHEAD OF AN AMPLIFYING MID-UPPER LEVEL TROUGH
OFFSHORE CA THIS PERIOD. THIS SHOULD SUPPORT LINGERING HEAVY
PRECIP AND SOME RUNOFF THREAT THROUGH PARTS OF THE S-CENTRAL
SIERRA AND COASTAL RANGES OF SRN CA WHERE SEVERAL ADDITIONAL
INCHES OF PCPN ARE POSSIBLE BEFORE ACTIVITY DIMINISHES. HEAVY
SNOWFALL AMOUNTS ALSO REMAIN LIKELY AT LOWERED ELEVATIONS THROUGH
THE SIERRA NEAR/OUTSIDE THE ELONGATED WPC MARGINAL THREAT AREA.

SCHICHTEL
$$





USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.